I want to include a page-level custom variable with my google analytics to track how many pages are cached and how many are not. This also means that I can divide the page speeds into two buckets, cached and not cached.
The way I thought I'd do it would be to inspect the HTTP headers using JS. But, I can't for love nor money find these HTTP headers that apparantly are supposed to be there. I've tried first using MOD REWRITE and then PHP. (I'm assuming I shouldn't expect headers when using MOD REWRITE, correct?)
Any idea what I'm doing wrong? And can I modify the MOD REQRITE rules perhaps to include a hint that a page has been cached that I can later find using JS?
PS. My site is The Modern Nomad.